Proof that I've watched Mythbusters too much, I analyzed the video frame by frame. If you look at the shadow of the car vs black strip on the road, you can see that the Tesla moved first by 0.34 seconds. At 100mph (aka 146 feet per second), that's 50' or almost three car lengths. Given that the M5 "lost" by less than a car length, I'd say "myth busted".

PS: they're at a road course, so what about lap times? Or did the M5 win by so much they decided not to air that?

EDIT: as for "torque" mattering from a stand still, both cars are (or at least the M5 is) tire-limited off the line, so which has more is irrelevant.